Metal-catalyzed asymmetric sulfoxidation, epoxidation and hydroxylation by hydrogen peroxide

• Hydrogen peroxide is a valuable oxidant for asymmetric sulfoxidation and epoxidation.
• Chiral iron and manganese porphyrins have been investigated for asymmetric hydroxylation.
• Non-heme iron complexes are suitable for asymmetric sulfoxidation.
• Simple oxidant, such as hydrogen peroxide, should be further intensively studied.
• Oxidation reactions catalyzed by iron and manganese complexes will continue to be a useful and important class of reactions for the future.

The development of environmentally benign reactions is an important goal in synthetic organic chemistry and chemical engineering. However, catalytic enantioselective oxidations using transition-metal complexes are limited when the oxidant is hydrogen peroxide. The two main difficulties of using hydrogen peroxide in the presence of transition metal complexes are the homolytic cleavage generating OH radicals and the catalase reaction with formation of dioxygen. The current applications of asymmetric sulfoxidation, epoxidation, dihydroxylation of alkenes and hydroxylation will be herein reported. Use of non-heme systems will be presented. The possibility of asymmetric oxidation catalyzed by metalloporphyrins will also be discussed.

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